In the face of spiralling carbon costs, the case for upgrading existing buildings rather than bulldozing and building anew is gathering pace.
French writer Marcel Proust once said that “the real voyage of discovery consists not in seeking new landscapes but in having new eyes”. So, I invite you to see two grey-field buildings on the edge of Sydney’s CBD through my eyes: the UTS Tower on Broadway and the Matavai and Turanga high-rise public housing estate towers at Waterloo Green.
Both sites have been subject to comprehensive master plans that did not offer a solution for recycling.
Such valuable, well-situated sites are prey to the pressures of development cycles. It is the norm to demolish and replace these types of buildings because they have reached their use-by date. But it is not that they are structurally inadequate, nor that they are unfit for habitation, but rather that they have reached the point in their lifecycle where they are no longer fashionable.
This practise is a heavy burden on the environment. The structure of a concrete-framed building generally has a lifespan of more than 200 years, and the huge amount of embodied energy and carbon of these buildings takes a similar timespan to be repaid.
Craig Roussac from Buildings Alive supports this in his studies of commercial buildings, and points out that the most sustainable building is not a new 6 Green Star building, but a 2 Green Star building that has been upgraded. That’s because the embodied energy of the old building is a sunk cost.
It is my view, in the new carbon economy we should add to the ledger the embodied energy debt of old buildings that are demolished to make way for the new. This view has been supported recently by the Climate Emergency movement that seeks to prioritise the recycling of old buildings before building new ones.
How do we re-love old buildings?
Today, we live with the consequences of our past neglect of this land and place. We cannot just restyle our buildings to conform to current fashion; we must deeply rethink them, act towards positive future environments and mindsets, find better ways to recycle them and create a symbiosis between the old and new. We must use an organic social perspective to assist people to live sustainably.
I propose an innovative step where new structures envelope the existing towers, providing new habitable spaces, and energy, food and water production mechanisms. I call this process Adaptive Building Symbiosis (ABS). The old and the new work symbiotically in a carbon-neutral framework.
The ABS approach to recycling allows maximal reuse of the host building fabric, locking in the enormous amounts of embodied CO2 of the existing concrete structures.
Ensheathing the existing concrete structures with the ABS matrix uses the high thermal mass of the existing structures for thermal balancing, considerably reducing heating and cooling demands.
ABS offers the thermal upgrade of reskinning, while retaining more of the existing building fabric and facades. The modular nature of ABS ensures quicker erection and less interruption to the host building.
ABS integrates, on site, sustainable energy, water harvesting and urban farming into the facades and roofs.
The most significant benefit is the increased population density created by ABS, creating new forms and highly sustainable and affordable architectural typologies.
The clear advantage of ABS is that there is no need to acquire more land. Profit generated by the increased density easily funds the costs of the sustainability features and drives overall affordability.
Case Study 1: UTS Tower, Broadway
Popularly referred to as Sydney’s ugliest building, the UTS Tower is an icon of Brutalist formalism. Having studied architecture there for six years, I admired its proportion and robustness while questioning the castrated views and poor natural lighting in the classrooms from the elevated ribbon windows set deeply into the rough precast reveal. You really have to be eight feet tall to get a glimpse of sky in this place!
The seed of ABS was planted into my subconscious at that time, and later awakened when UTS announced its masterplan for its campus, which bizarrely did not include the tower. Perhaps the tower was the architectural incarnation of the Gordian Knot.
The accompanying illustrations show the first iteration of ABS as a literal beehive of student accommodation ensheathing the monolith, with its decoration of micro wind turbines and articulated hyperbolic trough solar collectors combining to create a megawatt power station on the facades.
This rough diamond of a scheme was presented to UTS in 2010 but rejected on the grounds that the university was busy with its masterplan. Talk about a catch-22.
Case Study 2: Matavai and Turanga towers, Waterloo Green
As unloved public housing, the Matavai and Turanga towers at Waterloo Green represent an excellent opportunity to be transformed by ABS into affordable and sustainable housing for people subsisting on the Newstart Allowance.
Featuring rooftop greenhouses using the Polydome urban farming system, in this case ABS not only provides the most affordable housing, but it lowers costs for utilities, transport and food. ABS can treble the population of the Matavai and Turanga towers while decimating their carbon footprint. A 30-square-metre bedsit rented for $120 per week is completely possible.
The towers can be saved, repurposed into temporary accommodation or used for small-scale offices. The existing population can be rehoused elsewhere or continue to live in the towers, and 1000 more people can live there, sustainably and affordably.
The ABS concept is financially viable because there is no new investment in land; the host building continues to operate during the construction phase; there are no major demolition costs; and there is a saving in the cost of new building structures due to the structural support of the host.
Further, the increased population density on site is stimulated by local employment. This new green economy combines significant financial contributions from the food farms and energy and water generation and storage mechanisms.
ABS demonstrates that sustainability and affordability are complementary. Through the ABS process, a holistic building metabolism is created that links sustainable buildings and landscapes with a community that lives sustainably and that is involved in the teaching and learning of a sustainable culture. We can show the way forward, our carbon footprint can be massively reduced and it can pay its own way measured against all metrics.
The full influence of ABS will be cultural because the behavioural changes required in the transition to a low-carbon economy must be supported by structural changes in the real environment.